( sup 111 In-DTPA-D-Phe sup 1 )-octreotide, a potential radiopharmaceutical for imaging of somatostatin receptor-positive tumors: Synthesis, radiolabeling and in vitro validation

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Life Sciences; (United States)

DOI:https://doi.org/10.1016/0024-3205(91)90052-D· OSTI ID:5754467

Bakker, W H; Albert, R; Bruns, C; Breeman, W A.P.; Hofland, L J; Marbach, P; Pless, J; Pralet, D; Stolz, B; Koper, J W; Lamberts, S W.J.; Visser, T J; Krenning, E P ^[1]

---

1. Erasmus Univ., Rotterdam (Netherlands) Sandoz Pharma AG, Basel (Switzerland)

As starting material for a potentially convenient radiopharmaceutical, a diethylenetriaminopentaacetic acid (DTPA) conjugated derivative of octreotide (SMS 201-995) was prepared. This peptide, (DTPA-D-Phe{sup 1})-octreotide (SDZ 215-811) binds more than 95% of added {sup 111}In in an easy, single-step labeling procedure without necessity of further purification. The specific somatostatin-like biologic effect of these analogues was proven by the inhibition of growth hormone secretion by cultured rat pituitary cells in a dose-dependent fashion by octreotide, (DTPA-D-Phe{sup 1})-octreotide and non-radioactive ({sup 115}In-DTPA-D-Phe{sup 1})-octreotide. The binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to rat brain cortex membranes proved to be displaced similarly by natural somatosatin as well as by octreotide, suggesting specific binding of ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide to somatostatin receptors. The binding of the indium-labeled compound showed a somewhat lower affinity when compared with the iodinated (Tyr{sup 3})-octreotide, but indium-labeled (DTPA-D-Phe{sup 1})-octreotide still binds with nanomolar affinity. In conjunction with in vivo studies, these results suggest that ({sup 111}In-DTPA-D-Phe{sup 1})-octreotide is a promising radiopharmaceutical for scintigraphic imaging of somatostatin receptor-positive tumors.

• OSTI ID: 5754467
• Journal Information: Life Sciences; (United States), Vol. 49:22; ISSN 0024-3205
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
NEOPLASMS
SCINTISCANNING
RADIOPHARMACEUTICALS
CHEMICAL PREPARATION
SOMATOSTATIN
RECEPTORS
IN VITRO
INDIUM 111
RATS
VALIDATION
ANIMALS
BETA DECAY RADIOISOTOPES
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
INDIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RODENTS
SYNTHESIS
TESTING
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics
400703 - Radiochemistry & Nuclear Chemistry- Radioisotope Production